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Show MODS IE USEFUL Oil FARM What It Eats Decides Whether Feathered Songster Is Beneficial Bene-ficial or Injuriou-s, MANY FRIENDS OF FARMERS Department of Agriculture Offers to Tell Agriculturist Whether Inhabitants Inhabi-tants of Fields Are Doing More Good Than Harm. Whether a bird is beneficial or injurious in-jurious to growing crops depends almost al-most entirely upon what it eats. If it consumes harmful insects the bird is an ally of the farmer ; if it feeds largely on growing crops it may be an enemy. Not all birds are beneficial, bene-ficial, but the useful kinds far out-t5t out-t5t nrabs'IHaie'-fcjiK-toiiS, and so great is their value as insect "enwtroyers in the United States that to them the United States department of agriculture gives credit of being one of the greatest controlling con-trolling factors in limiting the development devel-opment of insect pests and in preventing prevent-ing many disastrous outbreaks. In the case of species which are abundant or which feed to some extent on crops, the question of their average aver-age diet becomes one of supreme importance im-portance and only by stomach examinations exami-nations can it be satisfactorily solved. Field observations have proved to be inconclusive. Birds are often accused of eating this or that product of cultivation, cul-tivation, when an examination of the stomachs shows the accusation to be false. Aid Offered to Farmers. The biological survey of the United States department of agriculture has conducted in the past few years a systematic sys-tematic investigation of the food of the species most common about farms and gardens and offers to supply infor- mation to any farmer in doubt as to whether his birds are an asset or a liability. Within certain limits birds eat the kind of food that is most accessible, especially when their natural food is scarce or wanting. Thus they sometimes some-times injure the crops of the farmer who has unintentionally destroyed their natural food in his improvement of swamp or pasture. Much of the damage done by birds and complained of by farmers and fruit growers arises from this very cause. The berry-bearing shrubs and seed-bearing weeds have been cleared away, and the birds have no recourse but to attack the cultivated cul-tivated grain or fruit which has replaced re-placed their natural food supply. Destroy Many Insects. The great majority of land birds subsist upon insects during the period of nesting and molting, and also feed their young upon them during the first few weeks. Many species live almost entirely upon insects, taking vegetable food only when other subsistence fails. It is thus evident that in the course of a year birds destroy an incalculable number of insects, and it is difficult to overestimate the value of their services serv-ices in restraining the great tide of insect in-sect life. In winter, in the northern part of the country, insects become scarce or entirely disappear. Many species of birds, however, remain during the cold season and are able to maintain life by eating vegetable food, as the seeds of weeds. Here again is another useful use-ful function of birds in destroying these weed seeds and thereby lessening lessen-ing the growth of the next year. |